I'm a former realtor and honestly save your money - do not get your license. For starters, your question shows that you don't know how the industry works, so a brief education...
1. As a realtor you are self employed. This means you are required to find your own leads, spend your own money for everything and you don't get paid until a transaction has closed. Repeat - brokers are not responsible to give you leads. You have to find your own leads.
2. The broker that you sign up with is responsible for your actions but is not your supervisor and cannot tell you how to do your job or what hours to work. However, depending on the broker there are policies in place that brokers will not tolerate and if you cross the line, they can terminate your contract with them. Example: if you post online a reply that may violate any part of the Fair Housing law, they can terminate you.
3. Researching commission structures among the different brokers is important but you need to research all the fees involved. You will have to pay these fees upfront and if you don't have the money, it can be a deal breaker.
4. How much money do you have to spend on marketing and advertising. This comes from your savings or if you work part time at another job - your income. Marketing and advertising yourself to get leads is expensive.
5. Will you be working as a realtor part time or full time? The difference is your clients expect you to be available on their schedule - not yours. If you work part time, this may interfere and it will take you twice as long to get a transaction closed than a full time realtor.
6. Example of fees that you have to pay for: broker fee, legal fee, MLS fee, lockbox fee, education, desk fee (some brokers charge for this, some don't), etc.
7. Yes, you can save all your receipts and deduct your expenses on your income tax return BUT you still pay for it upfront.